Such a hydraulic steering device is known from DE 195 11 501 A1. When a vehicle equipped with such a hydraulic steering device is driven in a so called “normal mode” the two fluid meters are arranged in parallel. In this case steering of the vehicle can be effected by rotating the steering wheel over a small angle. In a so called “emergency steering mode” there is no supply of hydraulic fluid under pressure. In this case one of the fluid meters is operated as auxiliary pump. Steering of the wheels of the vehicle requires a larger rotation of the steering wheel, however, with a reduced torque. Automatic switching between the two modes can be realized by means of the pressure at the supply port and by means of a spring acting in the opposite direction.
Another steering device of the kind mentioned above is known from US 2009/0199915 A1. In this steering device the flow meter valve means is arranged between the two fluid meters.
A further steering device is known from EP 1 212 231 B1 in which the fluid meter valve means is arranged in a housing surrounding a cardan shaft connecting the two fluid meters.
However, when such a steering device is used in a vehicle requiring a large volume flow for operating a steering motor the driving is rather uncomfortable for the driver. The driver has to perform many rotations with the steering wheel (or any other steering actuator) in order to turn the steered wheels as desired.